1. Field of the Invention
The present invention relates generally to retail point of sale systems, and more particularly to RFID scanning of retail goods.
2. Background of the Related Art
Point of sale (POS) systems are specialized computer systems used in retail environments for facilitating the checkout process, and which identify and account for items that a customer has selected for purchase. Modern POS systems typically include a POS terminal located at a checkout counter to facilitate the checkout process. A POS terminal typically includes a variety of user interface devices, such as a cash register, check/debit card/credit card reader, and a bar code scanner. The Universal Product Code (UPC) scheme is commonly used to uniquely identify items selected for purchase. The UPC scheme uses barcode symbology that has improved the speed and accuracy of checkout. The UPC scheme allows each item selected for purchase to be scanned in with an optical scanner, one item at a time, and cross-referenced with an electronic database containing price information for the associated item.
Various item-tracking solutions using radio frequency identification (RFID) tags have been proposed in an effort to provide even greater speed and accuracy than conventional UPC systems. RFID-based scanning systems typically involve an active scanning device, and a transponder in the form of an active, passive, or semi-passive RFID tag affixed to each item. RFID tags can be read from up to several meters away, and RFID scanners are capable of multi-directional reading, allowing RFID tracking systems to scan for multiple items in the vicinity of the scanner. Efforts to implement RFID-based scanning systems have included proposed ideas for scanning an entire shopping cart full of items at once in an effort to save time over individually scanning item barcodes. However, difficulties have arisen in obtaining an accurate accounting of shopping cart contents when scanning the entire shopping cart. For example, items near the center of a cart may not be reliably detected with an RFID scanner using existing technology.